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(No Model.)

J. S. DAVISON.

COVER FOR CHAMBER VESSBLS.

No. 329,441. Patented Nov. 3, 1885.

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UNITED STATES PATENT GFEICE.

JOHN S. DAVISON, OF GRANBURY, NEW JERSEY.

COVER FOR CHAMBER-VESSELS.

SPECIFICATION forming part of Letters Patent No. 329,441, dated November 3, 1885.

Application filed August 15, 1885. Serial No. 174,509. '(No model.)

To all ZUhOWI/ it may concern.-

Be it known that 1, JOHN S. DAVISON, a citizen of the United States, residing at Granbury, in the county of Middlesex and State of New Jersey, have invented a new and useful Improvement in Covers for Chamber-Vessels, of which the following is a specification, reference being had to the accompanying drawings.

My invention relates to an improvement in covers for chamber-vessels; and it consists in the combination, with arubber or other similar coveringhaving an opening in its center and a weighted ring at its 'circumference, of the flexible cap secured at its circumference to the outer edge of the cover, and having a loop or knob at its center, by means of which a partial vacuum may be formed in the vessel to cause the cover to secure the same air-tight and prevent the escape of bad odors, as will be more fully set forth hereinafter.

In the accompanying drawings, Figure l is a detailed perspective view of my invention, a portion of the cap being broken away to disclose the cover. Fig. 2 is a vertical sectional view of the same applied to a chambenvessel, the cap being shown collapsed in dotted lines and distended in solid lines, to exhaust the air from the vessel.

A represents the cover, which should be composed of a sheet of india-rubber or other similar substance, and is provided with an opening. B, at its center and avalve, B. The cover is circular in shape, and somewhat larger in diameter than the top of the vessel Z, to which it is applied, and at the edge of the cover is secured a weighted ring, 0, the function of which is to stiffen the cover and stretch the same, and also to hang down or fit over the outer edge of the chamber-vessel to fit the cover closely thereto. Also secured to the edge of the cover is an elastic cap, D, which is free from the cover at all other points, so that it may be collapsed upon the cover or drawn upwardly at the center above the cover, and to facilitate this operation the center of the cap is provided with a button, E; or a loop may be employed for the same purpose, if preferred. This cap should preferably be made ornamental and attractive, and to heighten this effect I provide a fringe, F, around the edge, which serves to partly hide the vessel. The cover is placed on the vessel, with the weighted ring around the top edge of the latter, the rubber cover being thus stretched across the top of the vessel, as shown at Fig. 2.

In order to render the coverair-tight, to prevent the escape of load odors from the vessel, the button of the cap is grasped and raised vertically, so as to distend the cap above the cover, as shown in solid lines in Fig. 2. This causes a partial vacuum to be formed in the vessel by drawing the air therefrom up through the opening B between the cover and the cap, which causes the pressure of the external air to force the cover down upon the top of the vessel with considerable pressure at all points, and thus render the joint between the cover and the top of the vessel air-tight. As the air is drawn up into the cap the valve B closes the opening, to retain the air in the cap and prevent it from returning into the vessel.

Having thus described my invention, I claim The cover for ch amber-vessels, made of rubber or other similar material, and having the central opening and the valve, and the weighted ring at its edge to encircle the top of the vessel, and the expansible cap secured at its edge to the edge of the cover, and having the central button or loop, whereby the cap may be distended to exhaust the air from the vessel and cause the cover to fit tightly thereon, sub stantially as described.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in presence of two witnesses.

JOHN S. DAVISON.

Witnesses:

S. J. GHAMBERLIN, GEORGE B. MERsHoN. 

